Henry greenfield



HENRY GREENFIELD, OF*N EW YORK, N.

Letters Patent No. 80,943,dated August 11, 1868.

MODE 0? GANGELLI'NG POSTAGE AND REVENUE-STAMBS.

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TO ALL WHOM IT MAY CONCERN:

Be it known that I, HENRY GREENFIELD, of New York, in the county and State of New York, have invented a new and useful Improvement in Postage and Revenue-Stamps, and in the Method of Cancelling the same; and I do hereby declare the following to be a. full, clear, and exact description thereof, which will enable those skilled in the art to make and use the same. I I

This invention consists in preparing the paper from whiehvthe stamps aretto be made, or the stamps, after they have been completed, with a suitable chemical, such as acetate of lead, and exposing them afterwards, for the purpose of cancellation, to the action ofanother chemical, such as sulphate of ammonia, or the fumes of sulphur, in such a manner, that, by printing or stamping with a solution of sulphate of ammonia, or other suitable ehemicaL'each single stamp can be efi'ectually cancelled, and by applying fumes of sulphur or other chemical,

in a gaseous form,a large quantity of stamps can be cancelled simultaneously, thereby saving much time and labor.

In carrying out my invention, I prepare the paper on which the stamps are to be printed, or the stamps themselves, after't hey have been printed, with acetate of lead, or any other-chemical which has no effect on-the printing-ink. After a stamp of this kind has been'attaehed to a letter or other paper, document, or article, I cancel thcsenie by stamping it with a solution of sulphate of ammonia, or other chemical, which, when brought in contact with the lead, salt, or other chemical previously applied tothe paper, will discolor the same, for instance, cause it to assume a brown tint, which cannot be removed without defacing the stamp entirely, and thus the object of cancellation is effected without fail.

In large oflices, where a large number of stamps have to be cancelled every day, I propose to enclose the letters, documents, or other articles to which the stamps, areattached, in a box, which can be filled with fumes of sulphur, or other chemical in a gaseous state, which, when coming in contact with the prepared stamps, will discolor the same in the same manner as the application of a solution of sulphate of ammonia or other chemical.

By these means I am enabled to cancel a large number of stamps simultaneously in little time, and with comparatively very little labor. c

Having thus described my invention, what I claim as new, and-desire to secure by Letters Patent, is-

A postage or revenue-stamp, prepared with acetate of load, or other chemical, so that it can be cancelled by the action of sulphate of ammonia .or otherchemical, as a new article of manufacture.

Also, the within-described process of'caneelling postage or revenue-stamps simultaneously in quantities,

by exposing them to the action of fumes of sulphur, or of other chemicals in a gaseous form, substantially as set forth.

HENRY GREENFIELD.

Witnesses:

W. Hausa, E; F. KASTENHUBER. 

